Software Design For Transponder Test Equipment

With the development of the aviation industry,flight safety has become a key concern.Through the air traffic control system,aircraft can be monitored and information such as the relative positions of aircraft can be provided to avoid the occurrence of airborne hazards.In order to ensure that the air traffic control system works properly,the airborne transponder needs to be tested regularly,and the test equipment is used to simulate the ground interrogator to interrogate it and receive the answer signal to determine whether the function and index of the airborne transponder are normal.NET Framework development environment,Visual Studio development software and C#language,combined with MVC architecture to develop a programmable transponder test equipment software.The main work is as follows:1.For the research objectives of transponder test software,thesis divides the software into system software and application software for implementation,and carries out a hierarchical modular design for each part of the software.The system software includes the driver software of signal transceiver module and codec module and the design of program control interface control protocol,while the application software includes the design of signal simulation control,received information decoding display,signal waveform display and parameter measurement.2.Based on the study of the working principle of secondary radar,transponder system and rangefinder system,we also focus on the interrogation/response signal format and coding/decoding processing of ATCRBS/S mode transponder,analyze how to generate A/C/S mode interrogation signal,receive and decode the response signal,test the power,frequency,response probability,sensitivity and dynamic range and other parameters indexes.Combined with the analysis of the signal format of the interrogation/answer pulses of X and Y channels in DME test mode,the transmitting,receiving and decoding of the interrogation pulse pairs of airborne DME devices are simulated to complete the range measurement function test.3.According to the actual needs of the system,a double buffered ring queue is designed to increase the data transmission efficiency;to prevent the S-mode data chain from being interfered by the rest of the signals during communication,the S-mode data error protection and verification algorithm is designed to avoid incorrect decoding information;to be able to control the instrument remotely,the SCPI algorithm is designed to parse and process the command parameters in combination with the SCPI command;to facilitate the import and export of the test data,the NPOI of Excel class library is used to manage the test data.To facilitate the import and export of test data,the NPOI of Excel class library is used to manage the test data.4.In terms of human-computer interaction,combined with Measurement Studio in the waveform display and data tables and other related controls,the user can be designed through the visualization of the upper computer interface to control the signal parameters configuration(pulse timing parameters,frequency and power of the interrogation response,etc.)and its parameters output,but also to modify the relevant parameters,etc.,but also support the interactive interface to read the received signal information in real time The parameters and related data can be read in real time on the interactive interface.Finally,with the help of the self-developed transponder test equipment hardware,the software design index and function test of the transponder test software are completed to verify the reliability of the software.